iPhone

The new iPhone 5 swept you off your feet in September. It dazzled you with sapphire crystals and diamond-cut edges; vibrant, kaleidoscopic Retinas that seemed to peer straight into your soul; and longer battery life — when you were awake, so was it.

But something didn’t feel quite right. You couldn’t put your finger on it — but it was as if the iPhone didn’t trust you. As if it felt the need to track your every move.

You weren’t imagining things. Apple’s new iOS 6 does, indeed, come with a default setting that tracks your activity, gathering a constant stream of personal data. Apple’s advertising arm, iAd, uses that data to create a targeted, personal ad campaign based on your recent Googling of “romantic comedies,” that knitting app you downloaded, and the Thai restaurant you checked into last night.

This tracking isn’t new. Apple devices have long carried unique device identifiers, or UDIDs (think of it as your iPhone’s Social Security number), which third-parties used to seed phones with targeted ads. But after Congress raised privacy concerns last spring, Apple began using UDID data only “for its own purposes,” Mikey Campbell, associate editor at Apple Insider, explained to me in an email. In its place for third parties is a new iPhone tracking technology, according to Business Insider.

It’s called an Advertising Identifier, and it’s basically an anonymous device ID number so businesses can follow your activities, without knowing much else about you. When you surf Crate & Barrel searching for stainless steel cookware, for example, the site’s publisher may send your Advertising Identifier to an ad server. Later, expect to see a lot of steel spatulas pop up on your screen.

For a brief period after the release of the iPhone 5, the Advertising Identifier reportedly wasn’t working. That meant advertisers couldn’t see if their ads influenced a user’s decision to buy something or prompted him to install an app. (These activities are known as “conversion.”) But now, the feature is working.

Here’s the good news: You can turn it off — and send skulking advertisers on their way. But unlike most activities associated with Apple, shutting it down is somewhat counterintuitive.

Here’s how you fly under the iOS radar:

1. Press the Settings icon.

2. Scroll down and press “ General,” then “ About,” and then “Advertising.”

3. Turn “Limit Ad Tracking” on, so that it is, in fact, limiting the ad tracking.

Another method: The Support tab of Apple’s website offers instructions and a link to “opt out” of what it calls “interest-based iAds.”

However, this may not free you of all advertiser tracking. According to an Apple notice titled “About Ad Tracking,” all advertising networks will be required to use the new ID number in the future — so turning it off once should get you out of that system entirely. But “until advertising networks transition to using the Advertising Identifier, you may still receive targeted ads from other networks.”

What are those cryptic “ other networks?” Apple Insider’s Campbell thinks the phrase refers to “third-party analytics from ad networks.

And has Apple set a deadline for advertisers to transition to the new Advertising Identifier system?

Not yet, but “that could change if the mass media gets ahold of the info and runs with it,” Campbell says.